1、BS ISO 7919-3:2009 ICS 17.160 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Mechanical vibration Evaluation of machine vibration by measurements on rotating shafts Part 3: Coupled industrial machinesThis British Standard was published under the authority of
2、the Standards Policy and Strategy Committee on 31 March 2009 BSI 2009 ISBN 978 0 580 64742 0 Amendments/corrigenda issued since publication Date Comments BS ISO 7919-3:2009 National foreword This British Standard is the UK implementation of ISO 7919-3:2009. It supersedes BS ISO 7919-3:1996 which is
3、withdrawn. The UK participation in its preparation was entrusted to Technical Committee GME/21/5, Vibration of machines. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a c
4、ontract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations.BS ISO 7919-3:2009Reference number ISO 7919-3:2009(E) ISO 2009INTERNATIONAL STANDARD ISO 7919-3 Second edition 2009-02-01 Mechanical vibration Evaluation of ma
5、chine vibration by measurements on rotating shafts Part 3: Coupled industrial machines Vibrations mcaniques valuation des vibrations des machines par mesurages sur les arbres tournants Partie 3: Machines industrielles couples BS ISO 7919-3:2009 ISO 7919-3:2009(E) PDF disclaimer This PDF file may con
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9、rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of
10、 the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedBS ISO 7919-3:2009 ISO 7919-3:2009(E) ISO 2009 All rights reserved iiiForeword ISO (the
11、International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee
12、 has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnic
13、al standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bo
14、dies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying an
15、y or all such patent rights. ISO 7919-3 was prepared by Technical Committee ISO/TC 108, Mechanical vibration, shock and condition monitoring, Subcommittee SC 2, Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures. This second edition cancels a
16、nd replaces the first edition (ISO 7919-3:1996), of which it constitutes a minor revision. It also incorporates the Technical Corrigendum ISO 7919-3:1996/Cor.1:2007. ISO 7919 consists of the following parts, under the general title Mechanical vibration Evaluation of machine vibration by measurements
17、 on rotating shafts: Part 1: General guidelines Part 2: Land-based steam turbines and generators in excess of 50 MW with normal operating speeds of 1 500 r/min, 1 800 r/min, 3 000 r/min and 3 600 r/min Part 3: Coupled industrial machines Part 4: Gas turbine sets with fluid-film bearings Part 5: Mach
18、ine sets in hydraulic power generating and pumping plants BS ISO 7919-3:2009 ISO 7919-3:2009(E) iv ISO 2009 All rights reservedIntroduction This part of ISO 7919 specifies guidelines for measuring transverse shaft vibration on coupled industrial machines. Evaluation criteria, based on previous exper
19、ience, are given for use as guidelines for assessing the vibratory conditions of such machines. A general description of the principles that are generally applicable for the measurement and evaluation of shaft vibration of non-reciprocating machines is outlined in ISO 7919-1. BS ISO 7919-3:2009 INTE
20、RNATIONAL STANDARD ISO 7919-3:2009(E) ISO 2009 All rights reserved 1Mechanical vibration Evaluation of machine vibration by measurements on rotating shafts Part 3: Coupled industrial machines 1 Scope This part of ISO 7919 gives guidelines for applying evaluation criteria of shaft vibration under nor
21、mal operating conditions, measured at or close to the bearings of coupled industrial machines. These guidelines are presented in terms of both steady running vibration and any amplitude changes which can occur in these steady values. The numerical values specified are not intended to serve as the on
22、ly basis for vibration evaluation since, in general, the vibratory condition of a machine is assessed by consideration of both the shaft vibration and the associated structural vibration. This part of ISO 7919 applies to coupled industrial machines with fluid-film bearings, having maximum continuous
23、 rated speeds in the range 1 000 r/min to 30 000 r/min and not limited by size and power, comprising steam turbines, turbocompressors, turbogenerators, turbofans, electric drives and associated gears, where relevant, and rotodynamic pumps (turbo pumps). The information relating to pumps provided in
24、this part of ISO 7919 complements that given in ISO 10816-7. In particular, the conditions for in-situ operation, performing acceptance tests and the influence of bearing clearance given in ISO 10816-7 shall be taken into account when evaluating the shaft vibration of pumps This part of ISO 7919 is
25、neither applicable to land-based steam turbine-generator sets for power stations with outputs greater than 50 MW (see ISO 7919-2), nor machine sets in hydraulic power generating and pumping plants with outputs of 1 MW or greater (see ISO 7919-5). 2 Normative references The following referenced docum
26、ents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 7919-1, Mechanical vibration of non-reciprocating machines Measurements on
27、rotating shafts and evaluation criteria Part 1: General guidelines BS ISO 7919-3:2009 ISO 7919-3:2009(E) 2 ISO 2009 All rights reserved3 Measurement procedures The measurement procedures to be followed and the instrumentation which shall be used are specified in ISO 7919-1. In industrial machines, s
28、haft vibration relative to the bearing is normally measured. Therefore, unless stated otherwise, this part of ISO 7919 always refers to relative vibration displacement. In view of the relatively high rotational speeds involved with industrial machines, measuring methods using non-contacting transduc
29、ers are most common and are generally preferred on rotor elements with operating speeds of 3 000 r/min and above. For monitoring purposes the measuring system shall be capable of covering overall vibration up to a frequency equivalent to 2,5 times the maximum service speed. However, it should be not
30、ed that for diagnostic purposes it might be desirable to cover a wider frequency range. 4 Evaluation criteria The criteria for vibration magnitude, changes in vibration magnitude and operational limits are given in Annex A. The vibration magnitude is the higher value of the peak-to-peak displacement
31、 measured in two selected orthogonal measurement directions. The values presented are the result of experience with machinery of this type and, if due regard is paid to them, acceptable operation can be expected. If only one measuring direction is used, care should be taken to ensure that it provide
32、s adequate information (see ISO 7919-1). The criteria are presented for the specified steady-state operating conditions at the rated speed and load ranges. They apply for normal slow changes in load but do not apply when different conditions exist or during transient changes, for example during star
33、t-up and shut-down and when passing through resonance ranges. In these cases alternative criteria are necessary. It should be noted that overall judgement of the vibratory state of a machine is often made on the basis of both shaft relative vibration as defined above and of measurements made on non-
34、rotating parts (see ISO 10816-3) 2 . BS ISO 7919-3:2009 ISO 7919-3:2009(E) ISO 2009 All rights reserved 3Annex A (normative) Evaluation criteria for relative shaft vibration of coupled industrial machines under specified operating conditions A.1 General Two evaluation criteria are used to assess the
35、 relative shaft vibration of coupled industrial machines, measured at or close to the bearings. One criterion considers the magnitude of the observed broad-band relative shaft vibration; the second considers changes in magnitude, irrespective of whether they are increases or decreases. Caution shoul
36、d be exercised when using the criteria presented in Annex A to ensure that no contact occurs between the rotating shaft and stationary parts. Therefore, in certain cases the shaft displacement limits given in this part of ISO 7919 may exceed the available clearance. In such cases the evaluation zone
37、 limits should be adjusted accordingly. A.2 Criterion I: Vibration magnitude at rated speed under steady operating conditions This criterion is concerned with defining limits for shaft vibration magnitude consistent with acceptable dynamic loads on the bearings, adequate margins on the radial cleara
38、nce envelope of the machine, and acceptable vibration transmission into the support structure and foundation. The maximum shaft vibration magnitude observed at each bearing is assessed against four evaluation zones established from international experience. A.2.1 Evaluation zones The following typic
39、al evaluation zones are defined to permit a qualitative assessment of the shaft vibration of a given machine and to provide guidelines on possible actions. Zone A: The vibration of newly commissioned machines normally falls within this zone. Zone B: Machines with vibration within this zone are norma
40、lly considered acceptable for unrestricted long- term operation. Zone C: Machines with vibration within this zone are normally considered unsatisfactory for long-term continuous operation. Generally, the machine may be operated for a limited period in this condition until a suitable opportunity aris
41、es for remedial action. Zone D: Vibration values within this zone are normally considered to be of sufficient severity to cause damage to the machine. BS ISO 7919-3:2009 ISO 7919-3:2009(E) 4 ISO 2009 All rights reservedA.2.2 Evaluation zone limits In accordance with present accumulated experience of
42、 shaft vibration measurements in this field, the recommended values for the zone boundaries are inversely proportional to the square root of the maximum operating speed of the shaft, n (in revolutions per minute). The recommended values illustrated in Figure A.1 are derived from Equation (A.1), Equa
43、tion (A.2) and Equation (A.3): Zone A/B boundary limit, in micrometres (p p) 4 800 m Sn = (A.1) Zone B/C boundary limit, in micrometres (p p) 9 000 m Sn = (A.2) Zone C/D boundary limit, in micrometres (p p) 13 200 m Sn = (A.3) NOTE For a definition of S (pp) , see ISO 7919-1. These values are not in
44、tended to serve as acceptance specifications, which shall be subject to agreement between the machine manufacturer and the customer. However, they provide guidelines for ensuring that gross deficiencies or unrealistic requirements are avoided. In certain cases, there can be specific features associa
45、ted with a particular machine, which would require different zone boundary values (lower or higher) to be used. For example, with a tilting pad bearing it might be necessary to specify alternative vibration values, whilst in the case of an elliptical bearing different vibration criteria can apply fo
46、r the directions of maximum and minimum bearing clearance. In particular, it should be recognized that the allowable vibration can be related to the journal diameter since, generally, running clearances will be greater for larger diameter bearings. Consequently different values can apply for measure
47、ments taken at different bearings on the same rotor line. In such cases, it is normally necessary to explain the reasons for this and, in particular, to confirm that the machine will not be endangered by operating with higher vibration values. Higher values of vibration can be permitted at other mea
48、suring positions and under transient conditions, such as start-up and run-down (including passage through critical speed ranges). A.3 Criterion II: Change in vibration magnitude This criterion provides an assessment of a change in vibration magnitude from a previously established reference or baseli
49、ne value for particular steady-state conditions. A significant increase or decrease in shaft vibration magnitude can occur which would require some action even though zone C of Criterion I has not been reached. Such changes can be instantaneous or progressive with time and can indicate that damage has occurred or be a warning of an impending failure or some other irregularity. Criterion II is specified on the basis of the change in shaft vibration magnitude occurring under steady-state operating con
